<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>画布的移动</title>
  <style>
    body{
     margin: 0;
     padding: 0;
     position: absolute;
     top: 0;
     left: 0;
     right: 0;
     bottom: 0;
     }
   .container {
     width: 100%;
     height: 100%;
     display: flex;
     align-items: center;
     justify-content: center;
   }
   #canvas {
     width: 500px;
     height: 500px;
     border: 2px solid green;
   }
 </style>
</head>
<body>
  
  <!-- <canvas id="canvas" style="width: 500px; height: 500px;"></canvas> -->
  <div class="container">
    <div>
      <button @click="openDraw">开始标注</button>
      <button @close="closeDraw">结束标注</button>
    </div>
    <canvas id="canvas" width="500px" height="500px"></canvas>
  </div>
  <script src="./index.js"></script>
</body>
</html>